HelloSign sendSignatureRequest ($ request) не работает ошибка выброса

Я новичок в HelloSign, когда я пытаюсь отправить запрос на подпись в hellos sign после появления ошибки ..

       Fatal error: Uncaught HelloSign\Error: [file not found]
File does not exist. Please use an absolute file path. thrown in
C:\wamp\www\NewHelloSign\library\HelloSign\AbstractResource.php on line 216


<?
require_once('HelloSign\Client.php');

require_once('HelloSign\BaseException.php');
require_once('HelloSign\AbstractObject.php');
require_once('HelloSign\AbstractList.php');
require_once('HelloSign\Signer.php');
require_once('HelloSign\SignerList.php');
require_once('HelloSign\SignatureList.php');
require_once('HelloSign\AbstractResource.php');
require_once('HelloSign\Account.php');
require_once('HelloSign\BaseException.php');
require_once('HelloSign\Error.php');
require_once('HelloSign\AbstractSignatureRequest.php');
require_once('HelloSign\SignatureRequest.php');









$client = new HelloSign\Client('MyID');
$request = new HelloSign\SignatureRequest;
$request->enableTestMode();
$request->setSubject('HelloSign Twilio API Demo - Sign This');
$request->setMessage('Check your phone for a secret pin to sign this document. We sent the pin to 1234567890 which should arrive shortly.');
$request->addSigner(new HelloSign\Signer(array(
'name' => 'jack',
'email_address' => '[email protected]',
'pin' => 'abcd1234'
)));
$request->addFile('http://localhost/NewHelloSign/library/omega-multi.pdf');
$response = $client->sendSignatureRequest($request);
print_r($response);
?>

$ response не возвращает никакого значения .., где я неправ, пожалуйста, предложите мне ..

Заранее спасибо..